title: Interaction of 1,3,2,4-benzodithiadiazines and their 1-Se congeners with Ph3P and some properties of the iminophosphorane products.
abstract: Interaction between Ph(3)P and 1,3,2,4-benzodithiadiazine (1); its 6,7-difluoro (2), 5,6,8-trifluoro (3) and 5,6,7,8-tetrafluoro (4) derivatives; and 5,6,8-trifluoro-3,1,2,4-benzothiaselenadiazine (5) proceeded via a 1:1 condensation to give Ph(3)P═N-R iminophosphoranes (1a-5a, R = corresponding 1,2,3-benzodichalcogenazol-2-yls), which are inaccessible by general approaches based on the Staudinger and Kirsanov reactions. In contrast, neither Ph(3)As nor Ph(3)Sb reacted with 1 and 4. Molecular structures of 1a-5a and 5 were confirmed by X-ray diffraction (XRD). The crystals formed by chiral molecules of 2a-5a were racemic, whereas the crystal of 1a was formed by a single enantiomer. In all of the Ph(3)P═N-R derivatives, one of the Ph rings is oriented face-to-face to the hetero ring, R. Upon heating to ∼120 °C in squalane (1a, 3a, 4a) or dissolving in chloroform at ambient temperatures (1a, 2a, 4a), the Ph(3)P═N-R derivatives generated the 1,2,3-benzodithiazolyls (1b-4b, respectively) whose identity was confirmed by electron paramagnetic resonance (EPR). 2,1,3-Benzothiaselenazolyls 5b and 6b were detected by EPR as the main paramagnetic products of solution thermolysis of 5 and its 5,6,7,8-tetrafluoro congener (6), respectively. Passing a chloroform solution of 4a through silica column unexpectedly gave 5-6-6-6 tetracyclic (9) and 6-10-6 tricyclic (10) sulfur-nitrogen compounds, which were characterized by XRD.
authors.affiliation: Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia.
authors.forename: Alexander Yu
authors.initials: AY
authors.lastname: Makarov
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Zhivonitko
authors.forename: Arkady G
authors.initials: AG
authors.lastname: Makarov
authors.forename: Samat B
authors.initials: SB
authors.lastname: Zikirin
authors.forename: Irina Yu
authors.initials: IY
authors.lastname: Bagryanskaya
authors.forename: Victor A
authors.initials: VA
authors.lastname: Bagryansky
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Gatilov
authors.forename: Irina G
authors.initials: IG
authors.lastname: Irtegova
authors.forename: Makhmut M
authors.initials: MM
authors.lastname: Shakirov
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Zibarev
mesh_terms: D001581:Benzothiadiazines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C519083:1,3,2,4-benzodithiadiazine; D001581:Benzothiadiazines; D009943:Organophosphorus Compounds